Recent improvements in weapon guidance technology employed to guide weapons on to an intended target and the resulting gains in weapon delivery accuracy combined with an improved knowledge of a location of the target have provided the ability to achieve reliable weapon impact on a selected target with zero or nearly zero circular error of probability. The impact of a weapon directed by guidance systems on the selected target is highly accurate within a very high measure of probability. Discrete targets, that is targets encompassing small areas such as a single vehicle, a bunker, a building, a petroleum storage tank within a petroleum farm, and other like objects, are readily struck with guided weapons.
Unitary warheads employed in weapons, currently in military inventory to attack targets such as discrete targets, contain a large amount of chemically based explosives. Explosives or an explosive material generally refers to a material capable of generating a violent chemical reaction of short duration that induces a substantial pressure wave. The detonation and the associated high temperature, pressure shock wave, fragments, and shrapnel generated is nominally more than sufficient to cause extensive damage to the selected target. In addition to the selected target, however, the unitary warheads often damage other objects, features, and people not associated with the target and beyond its physical limits thereby introducing the almost certain potential of collateral damage. Collateral damage refers to items, features and people not associated with the target that are not intended to be injured or destroyed by the weapon.
Another source of potential collateral damage is the need to attack targets repeatedly, especially if battle damage assessments (or “bomb damage assessments”) are ambiguous. With each attack, the probability of collateral damage increases. Thus, the ability to plan and assess attacks is another element of addressing the undesired results of such attacks.
In a like manner, improvements in weapon guidance technology have provided the ability to accurately guide weapons to targets encompassing an extended area. Weapons carrying a multitude of bomblets, often referred to as submunitions such as combined effects bomblets, can achieve nearly uniform and significantly dense, overlapping patterns over the intended target area. Submunitions provide a degree of penetration capability, and induce blast, fragmentation and incendiary reactions to damage or destroy the intended target. Recent surveys of post operations battlegrounds and training sites, however, have revealed that on the order of five percent to 23 percent of the dispensed submunitions failed to detonate (see, for instance, “Operation Desert Storm: Casualties Caused by Improper Handling of Unexploded U.S. Submunitions,” by Government Accounting Office Report NISAD-93-212, August 1993, which is incorporated herein by reference).
Each unexploded submunition is a latent and potentially lethal hazard to people and livestock in the area, as well as to explosive ordnance disposal operations and other activities that may cause contact with or motion of an unexploded submunition. The unexploded submunition and, more generally, unexploded ordnance is a serious problem and requires skilled personnel who are trained and equipped at great expense to find, identify, and disable such items. The political implications and efforts to locate, avoid, and dispose of unexploded ordnance, and the associated latent lethal effects of these items before they are dealt with, are of such magnitude that cluster submunitions are now being viewed with disdain similar to that of land mines. As a result, a number of countries are moving to ban dispensed munitions, combined effect bomblets and other similar submunitions from their weapons inventory.
While the energetic nature of chemical explosives, sensitivity of fuzes, and the warhead incorporating these elements, when properly excited, produces the desired destructive force, these same elements, when inadvertently and unintentionally exposed to stressing environments, can also produce the same or similar destructive forces with disastrous consequences. As an example, in World War II and the Viet Nam war, United States Navy aircraft carriers, embarked aircraft and shipboard personnel experienced extensive damage, destruction, injury, and death when ready weapons went high order during unintended events. Ready weapons are those weapons that have been removed from the protective magazines and storage bunkers and are at a state of near immediate use. Thus, ready weapons are less protected from stressing environments (e.g., hot exhaust from aircraft engines, stray electromagnetic stimulation, enemy action and other similar events) that can induce an inadvertent high order detonation providing the full or nearly full destructive force of the warhead. The volatile nature of the warhead is of extreme concern to the operating forces. Extensive research, strict design criteria, and ancillary requirements at increased cost and complexity of the life cycle design of the weapon has reduced this threat somewhat. Significant opportunities for undesirable events such as recounted herein still remain.
Many references in the past have attempted to address the safety issues associated with weapons including the types of material employed therewith. For a better understanding of exemplary weapons, peripherals and materials that address such issues, see the following references, namely, U.S. Pat. No. 3,625,152 entitled “Impact-Actuated Projectile Fuze,” to Schneider, et al, issued Dec. 7, 1971, U.S. Pat. No. 3,887,991 entitled “Method of Assembling a Safety Device for Rockets,” to Panella, issued Jun. 10, 1975, U.S. Pat. No. 4,775,432 entitled “High Molecular Weight Polycaprolactone Prepolymers Used in High-energy Formulations,” Kolonko, et al., issued Oct. 4, 1988, U.S. Pat. No. 5,311,820 entitled “Method and Apparatus for Providing an Insensitive Munition,” Ellingsen, issued May 17, 1994, U.S. Pat. No. 5,348,596 entitled “Solid Propellant with non Crystalline Polyether/inert Plasticizer Binder,” to Goleniewski, et al., issued Sep. 20, 1994, U.S. Pat. No. 5,567,912 entitled “Insensitive Energetic Compositions, and Related Articles and Systems and Processes,” to Manning, et al., issued Oct. 22, 1996, U.S. Pat. No. 6,253,679 entitled “Magneto-inductive On-command Fuze and Firing Device,” to Woodall, et al, issued Jul. 3, 2001, U.S. Pat. No. 6,338,242 entitled “Vented Mk 66 Rocket Motor Tube with a Thermoplastic Warhead Adapter,” to Kim, et al., issued Jan. 15, 2002, which are incorporated herein by reference. While the aforementioned references, and others for that matter, attempt to address specific problems associated with weapon unintended consequences, continued study and improvement is necessary to reduce unintended events and consequences associated with the use of weapons and weapon systems.
Accordingly, what is needed in the art is an effective weapon and warhead that is adequate for the mission and very limited and specific to its area of intended destruction. The destructive force of the warhead should be confined to the intended target without inflicting damage to adjacent and non targeted structures, features, and innocent personnel. Additionally, the warhead should be substantially insensitive to stressing environments to significantly reduce the exposure to inadvertent explosion.